1. Field of the Invention
The invention generally relates to air filters used in reciprocating engines. Specifically, the invention relates to pre-molded one-piece end caps for safety air filter elements installed in reciprocating engines used for heavy off-road applications, such as bulldozers, skid steer loaders, transfer trucks, etc.
2. Description of the Background Art
In heavy off-road applications, a typical air filter assembly comprises a first or outer air filter designed to clean the air of most substances that would damage the engine. A second, or “safety” air filter is positioned concentrically within, or down stream, of the first air filter to further filter any contaminates that make it past the first filter, should the first or outer filter become compromised and allow the passage of unfiltered air. The safety air filter also provides air inlet protection while the first or outer filter is changed.
A typical safety air filter assembly comprises a cylindrical filter body of wire mesh, fiberglass, or metal supporting structure, fixedly attached to a filter media, such as paper, foam, plastic, or any combination thereof. A first end of the filter assembly is comprised of soft pliable material, such as polyurethane. The soft material is molded integrally with the cylindrical expanded core and filter media. An opposite or second end of the filter body is comprised of a structurally rigid and substantial material, such as metal, fiberglass, or hard plastic.
Currently, the molding process required to manufacture the first pliable end of the filter is relatively expensive, time consuming, and may provide an inferior bond between the end cap and the body of the filter. In order to address these deficiencies, the present invention has been developed. The invention may be used in any filter system, but is designed primarily for the end caps of safety air filters in heavy off-road vehicles. In operation, the filter functions to ensure that the air-flow path into an engine is always protected, while at the same time minimizing air filter production costs.